Police had tried to stop UK Uncut activists from protesting inside the Fortnum and Mason department store in central London on March 26. Photograph: Carl Court/AFP/Getty Images

Two dozen anti-cuts activists have asked the courts to be put back on trial for alleged aggravated trespass despite already having their charges dropped by the Crown Prosecution Service.

The 21 members of UK Uncut say they have used their legal right to "revive" their cases to both prove their innocence and to stand in solidarity with 30 fellow activists who continue to face trial for the same alleged offence at London luxury food retailer Fortnum and Mason, last March.

The move has been labelled the "Spartacus defence" after the scene in the Kirk Douglas movie when dozens of rebellious Roman slaves all declare "I am Spartacus" in order to stop soldiers from identifying and executing their leader.

The CPS confirmed that they would contact all those asking to revive their prosecutions.

Police had arrested over 150 UK Uncut activists who occupied theinside of the Piccadilly store on March 26. The mass arrest was hailed as a triumph of effective law enforcement despite the senior officer at the scene describing the in-store occupation as "sensible" and "non-violent".

However it continued with the prosecution of 30 members alleging that they represented an "organising element" partly because of the "banners, cordon tape and leaflets" in their possession.

In a letter to the court dated the 21 August, solicitors who are representing the members wrote, "Our clients consider it unfair, disproportionate and arbitrary for the Crown to prosecute the 30 defendants against whom proceedings are continuing."

It is understood that many of the 21 defendants may now appear at Westminster magistrates court in October.

Tom Pursey, from the Fortnum 145 campaign said that he was willing to face prison despite having previously escaped the criminal proceedings. "I decided to declare 'I am Spartacus' because I think the arrest of 145 inside Fortnum for sitting in a shop and holding a simple sit in protest is completely absurd and alarming in terms of the right to protest.The CPS should drop all the cases."

He said the defendants didn't know each other that well but that this represented a basic form of solidarity and the "big society spirit".

It is understood that the CPS is still reviewing all the cases in connection with the March 26 protest, leaving open the possibility of all the remaining charges being dropped in their entirety.

• This article was amended on 8 September 2011 to clarify the position of those arrested inside the store